Assessment of Naturally Occurring Radioactive Materials (NORM) at Oil and Gas Industry in Pakistan

Oil and gas drilling and processing operations have potential to unearth the naturally occurring radionuclides and subsequently accumulate them in the processing equipment. Pakistan Nuclear Regulatory Authority (PNRA) carried out a detailed study at Eleven (11) oil and gas fields with the objective to evaluate the concentration of Naturally Occurring Radioactive Material (NORM). Initial screening of each field was performed through survey meter and dose rates at surface and 1m from all major equipment notably wellheads, separators, production manifolds, well tubing, storage tanks etc. were recorded. Majority of the measurements were in the range of natural background level (0.07 µSv/hr – 0.10 µSv/hr). However, at one facility, dose rate value of 15 µSv/hr was recorded. The estimated annual effective dose to the occupational workers based upon their occupancy at the identified radiation areas was 2.0 mSv.